Ajutage



April 26, 1927. 1,625,867

A. P. PLANT AJUTAGE Filed July 25, 1921 Patented- Apr. 26, 1927.

ANTOINE P. PLAUT, OF DETROITMICHIGAN, ASSIGNOR ONE-HALF T :ROBERTS BRASS MANUFACTURING COMPANY, MICHIGAN.-

OF DETROIT, MICHIGAN, A CORPORATION 0F AJUTAGE.

Application led 'July 23, 1921. Serial No. 486,941.

The invention relates toy ajutagesy which are commonly designated as nozzles, chokev tubes, or venturis, and used where an increase in the velocity of a fluid is required. Heretofore, the part of the ajutage used as the entrance for the fluid has been made with a curve that is generally called a Wellrounded entrance. The object of my invention is the provision of an ajutage through which a reater volume of fluid will flow in a given t1me with the same throat area than through an ajutage having a well-rounded entrance. In other words, the object of my invention is to provide an ajutage having increased eliiciency in operation. Another object of the invention resides in providing a construction of ajutage which is simple and cheap to manufacture as well as of light weight. With' these objects in view, the invention resides in the novel features of construction as more fully hereinafter set forth.

In the drawings:

Figure 1 is a central longitudinal section through a nozzle applied to a steam turine; l

Figure 2 is a side elevation partly broken away of a carburetor and showing 1n central prises the outer tu longitudinal section a choke tube.

As shown in Fi re 1 the nozzle comli: 1 having the closed end 2 through which axially passes the inner tube 3 having o en ends and forming the nozzle throat. 's throat tube is permanently secured to the closed end 2 with a fluid tight seal therebetween by any suitable means, as for example b welding, and has an external diameter which is less than the internal diameter of the outer tube so that a substantial annular chamber 4 is formed between the outer tube and the vinner portion of the throat tube. The inner end 5 of the throat tube 3 is curved or rounded to prevent the forming of eddies in the lluid passing through the throat tube.

In theory, the o eration of this fluid nozzle is as follows: e luid in taking the direction indicated by the arrow in,F1gure 1 passes along the tube 1 and builds up in the annular chamber/1, which is of substantial size, forming a body 4of fluid between the inn'er portion of the inner tube 3 and the outer tube 1 which extends beyond the inner end 5 of the innertube which allows the molecules of the fluid to follow the path of least resistance andto form their own curve before entering the inner or throat tube. vWith this arrangement, vthe resistance to the column of moving fluid is less than yin the case of a fluid nozzle having .a well rounded entrance. Furthermore, the velocity of the fluid flowing next to the wall of the outer Vpipe 1 is muchless than at the center of this pipe so that with a chamber around the entrance of the inner pipe 3, a less quantity of the slow moving fluid following the wall of the outer pipe Will enter the inner pipe whereby increase in flow of fluid is also secured.

In the construction shown in Figure l, are series of blades or buckets of the rotor of the turbine, 7 is a series of blades or buckets of the stator of the turbine. The inner tube 3 which leads the fluid to the turbine is preferably flared `outwardly in the direction of flow in accordance with the best principles of turbine design, thereby formin a restricted entrance `closely adjacent t e fluid pocket 4.

Figure 2 discloses a carburetor 11 having the induction passageway 12 through which the explosive mixture passes to the intake manifold (not shown). 13 is the nozzle which extends axially into the lower end of the choke tube 14 positioned within the. induction passageway and 15 is the air passagewa leading to the choke-tube. wall 16 of the choke tube leading from fits upper end to its restricted portion or throat is of the same taper as commonly used in choke tubes for carburetors, but instead of having a well-*rounded entrance the choke tube terminates at its throat and has its throat end 17 curved or rounded. Furthermore the outer wall of thethroat portion of the choke' tube is cut away to form the annular chamber 18 between the throat portion of the choke tube and the wall of the induction passageway, this -chamber being of substantial size.

From the above description, it will be readil seen that VI have provided a construction of ajutage which yhas greater elli- The inner ciency in operation than the type of ajutage formerly used; thatfthis ajutage is simple.

an induction conduit having a substantially straight portion extending in a single direction, a tapering tubular member not of venturi form entirel tion of said con uit, the small end of said tapering member being spaced from said outer induction A'conduit to form a surrounding annular pocket whereby a curved venturi passage 1s obtained at the entrance to said tubular member, the sides of said assage being formed by the fluid trappe by said annular pocket.

2. In a carbureter, the combination with an induction conduit having a substantially straight portion extending in a single diwithin the straight por-n rection, of a sleeve within said conduit having a tapered inner surface, the restricted portion of which is within the straight portion of said outer conduit, said sleeve having a tnin Wall adjacent the restricted portion spaced from the outer conduit to form an annular chamber close to said restricted portion, the entrance edge of said sleeve being slightly rounded to avoid sharp corners but not rounded sufficiently to form a venturi of the sleeve, air trapped by said pocket at the entrance to said sleeve forming a venturi eiect.

In testimony whereof I aiix my signature.

ANTOINE P. PLAUT. 

